In recent years there has been a growing demand for carbon dioxide (CO.sub.2) while economic sources have remained relatively limited. A significant contributor to the increased consumption of CO.sub.2 is the expanding sales of carbonated beverages including "light beers". While refrigeration is the leading use of CO.sub.2, the chemical and metal industries are important buyers of CO.sub.2. The injection of CO.sub.2 into wells for enhanced oil recovery is a modern development requiring large quantities of CO.sub.2.
Ammonia plants are estimated to provide by-product CO.sub.2 equivalent to about 70% of the demand for purified CO.sub.2. Hence, when the sales of ammonia decline, the problem of supplying the users of CO.sub.2 becomes acute.
Accordingly, a principal object of this invention is to open up a new source of CO.sub.2 heretofore untapped, especially land-fill gas.
Another important object is to provide an economically attractive process for purifying the CO.sub.2 from such new source.
A further object is to achieve very high recoveries of methane and purified CO.sub.2 from land-fill gas or like gas mixtures of methane and CO.sub.2.
Those and other objects and advantages of the invention will be evident from the description which follows.